Whitefly, techniques and organic treatments to avoid it


Whitefly is a tiny insect that attacks all kinds of plants, particularly:

hibiscus, geranium, greater celandine, fuchsia and certain vegetables from the vegetable patch such as tomato.

After forming a large colony under the leaves, these insects suck the sap of the plant and weaken it. They also make leaves sticky and cause sooty mold to appear.

A large-scale invasion can even lead to the plant’s demise.

Conditions that favor the spread of whitefly

Whitefly emergence conditionsThe main causes of whitefly appearing on plants are:

  • greenhouse growing
  • long, strong heat waves
  • dry atmosphere
  • low biodiversity
  • wide expanses of the same crop or flower
  • absence of protective hedges and obstacles

How to fight whiteflies?

Whitefly treatmentTraditional methods like insecticides or aphid treatments can be effective, even though they only target adult insects and don’t destroy eggs.

If those methods are applied, repeat treatment every 3 days over a 2 to 3 week period. Be careful! These products are often dangerous to breath in.

Organic treatments against whitefly

  • Treating whitefly naturallyPlace whitefly traps. In specialized horticulture stores, you can find sticky glue that can be applied on any yellow surface, since whiteflies are attracted by that color.
  • Some predator insects can help eliminate them. A tiny wasp called Encarsia formosa does just that, since it lays its eggs inside whitefly larvae. Another predator is a bug called Macrolophus caliginosus that eats these parasites.
  • Don’t use predator insects inside your house.
  • Lastly, it is also possible to spray an insecticidal soap based on permethrin. This last solution has been proven to be efficient.

In all above cases, you can bring infected plants to a cool room since these parasites need heat to develop.

Learn more about diseases

Images: CC BY 4.0: Mihajlo Tomić; own work: Rosalyn & Gaspard Lorthiois; Public Domain: Hugo Hulsberg, Scot Nelson